Nowadays software development is a challenging task as the number of programming languages, frameworks, libraries are increasing rapidly day by day.
Luckily, the number of resources to learn on the internet for free also increased a lot. There are a ton of free resources to learn almost everything on the internet.
There are lots of official documentation, blog posts, Udemy courses, YouTube videos etc.

Test

A curated collection of learning resources for Java and Spring developers, organized by category. Covers Spring framework blogs and YouTube channels (Josh Long, Baeldung, reflectoring.io, etc.), SQL/JPA/Hibernate/JOOQ resources (Vlad Mihalcea, Thorben Janssen), web development channels (Traversy Media, freeCodeCamp), and DevOps tutorials. Includes both written blogs and video content from well-known community contributors.

All the resources you ever need as a Java & Spring application developer